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June 2, 1931. E. GATHh llANN Re. 18,084

INGOT MOLD TOP 2 Sheet s-Sheet 1 Original Filed Aug 20, 1923 l mzamihwcntor,

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Reiaued June 2, 1931 UNITED STATES EMIL GATHMANN, OF BALTIMORE,MARYLAND, ASSIGNOR TO THE GATHMANN ENGINEERING COMPANY, OF BALTIMORE,MARYLAND, A CORPORATION OF MARY- LAND INGOT MOLD TOP Original No.1,621,402, dated March 15, 1927, Serial No. 658,371, filed August 20,1923. Application for reissue filed March-12, 1929. Serial No. 346,460.

This invention relates to the casting of ingots from either steel whichhas been deoxidized as much as possible or from partially deoxidizedsteel and it involves cer- I tain improvements in the shape or contourof the mold top.

One object of the invention is to so construct or sha e the chamber ofthe mold top that the portion of the ingot formed therein may have suchshape as to permit of its free contraction without interference orhindrance to such contraction from the walls of the mold top to thusprevent undue or harmful stressing of the outer walls or skin of theingot.

A further object of the invention is to so form the chamber of the moldtop that the portion of the ingot produced therem is shaped in suchmanner that it is adaptable for rolling or reduction into blooms orslabs when reheated without danger of excessive tears or surfacereduction cracks.

According to my present invention I pro- I vide a shrink head casing formolds having corners and salients of such kind and of such novel shapeas to properly match within the top of a mold chamber provided with asimilar contour of corners and salients.

The mold top is preferably made of fire brick or other good heatinsulating refractory material and it ma be formed in .one piece or insections and is of such size as to leave clear annular spaces betweenits outer side walls and the inner. walls of a mold chamber, whichspaces are of such width as to permit of the top being readily movedinto the mold chamber and withdrawn therefrom, but sufiiciently narrowso that the molten metal will not pass freely through the space whenthemold is poured.

The invention is clearly illustrated in the accompanying drawings, inwhich:

Figure 1 is a view partly in side elevation and partly in verticalsection of a mold in connection with which the mold top is used, myimprovements in this-instance beingapr plied to a big-end-up moldmounted on a suitable support or stool.

Figure 2 is a detail view in section of the shrink ead casing.

form of the shrink head casing which is inthis instance made insections.

The mold A shown in Figure 1 is a bigend-up mold. The mold chamber iscorrugated and is provided with corners and salients in the manner mostclearly shownin Figure 3, and these features are hereinafter described.The lower portion of the mold is necked-in as indicated at X, thecorrugatlons a: merging into the necked-in part of the mold as shown.The opening in the bottom ofthe mold is closed by a plugP which is ofservice in the stripping of the ingot from the mold when cast. The moldrests on a stool B of usual construction for Gathmann bigend-up molds.

The mold top is marked F in the drawings and it is formed with laterallyprojecti n lugs .1. These lugs are preferably located intermediatebetween the u per and lower ends of the mold top and preilerably theyrest on wedges or blocks G which hold the mold top at the desiredelevation.

As indicated in Figure 3, the mold top or shrink head casing has fourprimary. side walls a, a and eight secondary walls or salients b, b, thesecondary wall being connected to thep'rimary walls byarc-shaped partsor salients c, Each secondary wall I), 1; extends at an angle of from 5to from a tangent T connecting the two apexes of the salient of eachprimary wall. The mold chamber is similarly formed.

The advantages of this construction are that the corners of thesecondary walls where they join the salients arebetter acted upon by therolls in the reduction of the ingot in the initial passes, thus morefully insuring the absence of breaks or cracks during the reductionoperation.

In the preferred construction, the secondary'o'r corner walls extendinwardly'at an angle of from 5 to 15 from a tangent T connecting the twoapexes of the salients of each primary wall.

' It will be observed that the mold top, made in accordance with myinvention has a plurality of side walls which concaved or are belliedinwardly toward the center of the 7. mold top, the interior and exteriorofi the mold top having the same contour. These walls are oppositelyarranged as shown. At each corner two primary side walls are connectedon the outside by three outwardly 1o curved" salients .there being anoutwardly curved salient at the end of each primary side wall whichconnects by a straight wall (1 or d with a centrally arranged cornersalient b or b. Preferably the mold top is of the same i thicknessthroughout except where the lugs f are formed where the sides of thefeeder are thickened to that extent. It will be observedby reference toFi re 3 that the mold top isof substantially t e same contour, bothinside and outside as the mold chamber. The preferred radius for thesalients at the corhers is indicated in Figure 3. As shown, thereis atwo-inch radius for each of the 26 three salients at each corner.

I claim as my invention: 7 y 1. A mold top for ingot molds having achamber provided with four primary side walls of convex contour and fourwidened to corners, each provided with three curved salients interveningbetween the adjacent primary side walls of the feeder.

2. An ingot mold top havingja chamber provided wlth four primary sidewalls merging with four obtuse-angled corners, the

faces of which lie at a tangent of from 5- to 15 to a line parallel withthe vertex of theyadjacent primary side wall.

3. A mold top made of refractory heat- 40 insulating material having achamber provided with, four primary side walls oflongitudinally-corrugated contour merging with four obtuse-angledcorners,the faces of which lie at a tangent of from 5 to 15 to a line'45 parallel with the vertex of the adjacent primary side wall Intestimony whereof, I have hereunto subscribed my name.

a EMIL GATHMANN.

